This invention relates to a lift unit for lifting and emptying containers, particularly heavy duty plastic waste containers of the type generally referred to as "roll out" containers and are typically used by municipalities for waste collection. Refuse is placed by a business or home owner and rolled to the street periodically for collection. These containers are quite large and can hold between 100 and 200 pounds of waste material. For this reason refuse collection trucks are typically equipped with lift units which grasp the container in some fashion and lift it upwardly while inverting it sufficiently to cause the contents fall into the hopper of the truck.
Prior art lift units include types which squeeze the container between arms sufficiently tightly to enable the lift unit to be raised and emptied and types which use hooks to engage with hooks or bars molded into or attached to the containers. The hooks remain engaged while the lifting and emptying take place. While these methods usually achieve satisfactory results, squeezing the containers can puncture or otherwise damage the containers, particularly when sharp objects such as bottles reside within the container near the walls of the container. In bad weather, when the container is wet with rain or ice, the container may slip from the arms, damaging the container and perhaps injuring someone standing nearby.
Lifting the containers with hooks presents its own problems. When the truck is parked on a hill or slope, the lift unit may not vertically or laterally align itself with the hooks or bars on the container in the proper manner. Attempting to lift a container under these conditions can damage the container by bending the lifting bar or ripping it from its anchoring bracket. Recent advances the applicant, Toter, Inc., has made in molding plastic waste containers permits the incorporation of integrally molded enlarged lips and rims into the body of the container. These structures reinforce the container, particularly around the mouth of the container where it is subject to repeated deformation. By reinforcing the mouth of a container, the lid can be designed to fit more tightly and will fit properly for a longer period of time.